1364554 > 九、發明說明： 【發明所屬之技術領域】 本發明涉及成像技術，特別涉及一種成像鏡頭。 ^【先前技術】 近年來，隨著半導體技術之發展，應用于成像系統之 影像感測器，如電荷耦合器（Charge Coupled Device，CCD) 或補充性半導體（Complementary Metal Oxide Semiconductor，CMOS)裝置，在提高圖元之同時，朝小型化 •方向發展’以此滿足消費者對成像系統之成像品質及便攜 性之要求。 對應地，成像鏡頭需提高解析度、縮小尺寸，以配合 影像感測器組成成像品質較好、尺寸小之成像系統。 【發明内容】 有鑒於此，有必要提供一種成像品質較好、尺寸小之 成像鏡頭。 鲁 一種成像鏡頭’其從物側到像側依次包括：具有正光 焦度之第一透鏡、具有正光焦度之第二透鏡，具有負光焦 度之第三透鏡以及一感測元件，其中，該成像鏡頭滿足條 件式： D/TTL>1.23 0.3<G1R1/F1<0.4 其中，D為感測元件之最大有效圖元之尺寸；TTL為 第一透鏡靠近物侧之表面到成像面之間距離；G1R1為第一 6 1364554 透鏡靠近物側之表面之曲率半徑；F1為第一透鏡之焦距。 . 條件 D/TTL>1.23，限制了成像鏡頭全長； ^ 0.3<G1R1/F1<0.4保證了成像透鏡100之總長與球差及慧差 之間之平衡，以保證該成像鏡頭具有較好之成像品質及小 型化之優點。 【實施方式】 請參閱圖1，本發明較佳實施方式成像鏡頭100從物側 籲到像側依次包括具有正光焦度之第一透鏡10、具有正光焦 度之第二透鏡20、具有負光焦度之第三透鏡30以及一個感 測元件210。 成像時，光線自物側射入成像鏡頭100，依次經第一透 鏡10、第二透鏡20及第三透鏡30後彙聚于成像平面200 上。設置感測元件210如CCD或CMOS之感測面（未圖示） 于成像平面200處便可組成一成像系統。 鲁為減小成像鏡頭100之長度且具有較好之成像品質， 成像鏡頭100應滿足以下條件： (1) D/TTL>1.23 (2) 0.3<G1R1/F1<0.4 其中，D為感測元件210之最大有效圖元之尺寸；TTL 為第一透鏡10靠近物側之表面到成像面200之間距離； G1R1為第一透鏡10靠近物側之表面之曲率半徑；F1為第 一透鏡10之焦距。 7 1364554 tr 條件（1)限制了成像鏡頭100之總體長度。條件（2)保證 了成像鏡頭100之總長與球差及慧差之間之平衡’以保證 -該成像鏡頭100具有較好之成像品質。 優選地，成像鏡頭100還滿足條件式： (3) 0.8<G1R2/F1<1.2 條件（3)給出第一透鏡10靠近像側之表面之曲率半徑 G1R2與第一透鏡1〇之焦距F1之間之關係，可進一步保證 鲁整個成像鏡頭1〇〇之總長與球差及慧差之間之平衡，此外 可進一步縮短成像鏡頭整體長度，並降低製造成本。滿足 G1R2/F1<1.2可縮短成像鏡頭100全長，滿足0 8<gir2， 可防止第一透鏡10之像侧表面過曲導致透鏡不易研磨，增 加製造成本。 (4) -0.1<G2R2/F2<G2Rl/F2<-〇.〇2 條件（4)給出第二透鏡20靠近物側之表面之曲率半徑 參G2R1以及靠近像侧之表面之曲率半徑G2R2與第二透鏡2〇 之焦距F2之間之關係，可進一步保證整個成像鏡頭1〇〇之 總長與球差及慧差之間之平衡’此外可進一步縮短成像鏡 頭100全長，並降低製造成本。 (5) G3R1/F3<-1.5 (6) -l<G3R2/F3<-0.5 條件（5)和條件（6)分別給出了第三透鏡3〇靠近物側之 表面之曲率半徑G3R1以及靠近像側之表面之曲率半徑 8 1364554 G3R2與第二透鏡30之焦距F3之間之關係，可進一步保證 .整個成像鏡頭100之總長與球差及慧差之間之平衡，提高 _整個成像鏡頭100之成像品質。 另一方面，為修正色差，還限定成像鏡頭100滿足關 係式： (7) Vdl>52 (8) Vd2<23 ° 其中，條件（7)中Vdl為d光（波長為587.6納米，下同） 在第一透鏡10之阿貝數（abbe number);條件（8)中Vd2為d 光在第二透鏡20之阿貝數。 可以理解，為抑制雜散光對該成像鏡頭100成像品質 之影響，在第一透鏡10物側可設置一個光圈40以遮罩雜 散光。 以下結合圖2至圖7,以具體實施方式進一步說明成像 φ鏡頭100。具體實施方式中，第一透鏡10,第二透鏡20及 第三透鏡30之物侧及像側之兩個表面都採用非球面。以透 鏡表面中心為原點，光軸為X拍，透鏡表面之非球面面型 運算式為： ch2 · + l + ^l-(k+l)c2h2 其中，C為鏡面表面中心之曲率，k是二次曲面係數 kVFTF為從光軸到透鏡表面之高度，Σα/表示對Aihi 9 1364554 累加，i為自然數，Ai為第i階之非球面面型係數。 _ 以下列舉二較佳實施方式，並分別說明： ^ 第一實施方式 該成像鏡頭100之各光學元件滿足表1及表2之條件。 下列表1中分別列有由物側至相側之光表學面、各光 學表面之球面形態、在光軸上各光學面之曲率半徑（R)、 從物端到像端光轴上各面與後一光學表面之間距（D)、與 籲鏡片材質之折射率（nd)和阿貝數（Vd)。 表1 光學表面 球面型態 R D nd Vd 第一透鏡物侧 非球面 0.98 0.61 1.53 56 第一透鏡像侧 非球面 2.26 0.07 第二透鏡物侧 非球面 -1.17 0.37 1.585 30 第二透鏡像側 非球面 -1.24 0.96 第三透鏡物侧 非球面 -10.00 0.38 1.53 56 第三透鏡像侧 非球面 3.84 0.35 1364554 非球面係數列表如下： 表2 非球面 係數 第一透鏡 物側 G1R1 第一透 鏡像侧 G1R2 第二透 鏡物侧 G2R1 第二透 鏡像側 G2R2 第三透 鏡物側 G3R1 第三透 鏡像侧 G3R2 Α4 -0.0297 0.0148 -0.1782 0.0095 -0.1613 -0.1443 Α6 -0.0035 0.0169 0.0473 0.0339 0.0872 0.0538 Α8 -0.0282 -0.1359 -1.2170 0.3717 -0.0180 -0.0152 Α10 -0.0333 0.6288 8.1281 0.0818 0.0015 0.0021 Α12 -0.0211 0.0210 -15.8921 -0.3195 -3.4Ε-05 -0.0001 第一實施方式中成像鏡頭100之球差特性曲線、場曲 特性曲線及畸變之特性曲線分別如圖2、圖3及圖4所示。 圖2中，曲線f，d及c分別為f光（波長為435.8納米，下 同）、d光及c光（波長為656.3納米，下同）于成像鏡頭100 •之球差特性曲線（下同）。可見，第一實施方式之成像鏡頭 100對可見光（400-700納米）產生之球差被控制在 -0.05mm〜0.05mm間。圖3中，曲線t及s為子午場曲 (tangential field curvature)特性曲線及弧矢場曲（sagittal field curvature )特性曲線（下同）。可見，子午場曲值及弧矢 場曲值被控制在-0.05mm〜0.05mm間。圖4中，曲線為》^變 特性曲線（下同）。可見，畸變量被控制在-5%〜5%間。綜前， 儘管成像鏡頭100尺寸縮小，其產生之球差、場曲及畸變 11 1364554 卻被控制（修正）在較小之範圍内。 第二實施方式 該成像鏡頭100之各光學元件滿足表3及表4之條件。 下列表3中分別列有由物側至相側之光表學面、各光 學表面之球面形態、在光軸上各光學面之曲率半徑（R)、 從物端到像端光轴上各面與後一光學表面之間距（D )、與 鏡片材質之折射率（nd)和阿貝數（Vd)。 表3 光學表面 球面型態 R D nd Vd 第一透鏡物側 非球面 0.98 0.59 1.543 56.8 第一透鏡像側 非球面 2.05 0.08 第二透鏡物側 非球面 -1.22 0.38 1.585 30 第二透鏡像側 非球面 -1.26 1.05 第三透鏡物側 非球面 -10.00 0.32 1.515 57 第三透鏡像側 非球面 4.05 0.35 非球面係數列表如下： 表4 非球面 係數 第一透 鏡物側 G1R1 第一透 鏡像側 G1R2 第二透 鏡物侧 G2R1 第二透 鏡像側 G2R2 第三透 鏡物侧 G3R1 第三透 鏡像側 G3R2 12 1364554 A4 -0.0318 0.0044 -0.1949 -0.0006 -0.1803 -0.1529 A6 0.0075 -0.0565 -0.0303 -0.0176 0.0836 0.0530 A8 -0.0349 -0.1291 -1.2707 0.3407 -0.0166 -0.0147 A10 -0.0463 0.5642 8.7958 0.1384 0.0021 0.0021 A12 -0.0183 -1.5272 -17.7776 -0.2671 -0.0002 -0.0002 第二實施方式中成像鏡頭100之球差特性曲線、場曲 特性曲線及畸變之特性曲線分別如圖5、圖6及圖7所示。 鲁由圖5中可見，第二實施方式中之成像鏡頭100對可見光 (400-700納米）產生之球差被控制在-0.05mm〜0.05mm間。 由圖 6中可見，子午場曲值及弧矢場曲值被控制在 -0.05mm〜0.05mm間。圖7中可見畸變特性曲線之畸變量被 控制在-5%〜5%間。綜前，儘管成像鏡頭100尺寸縮小，其 產生之球差、場曲及畸變卻被控制（修正）在較小之範圍内。 本發明之成像鏡頭滿足條件式：D/TTL>1.23，限制了 成像鏡頭100之整體長度；0.3<G1R1/F1<0.4保證了成像透 _鏡100之總長與球差及慧差之間之平衡，以保證該成像鏡 頭1〇〇具有較好之成像品質。 綜上所述，本發明確已符合發明專利之要件，遂依法 提出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 13 1364554 【圖式簡單說明】 . 圖1為本發明成像鏡頭較佳實施方式之系統構成示意 圖。 圖2為本發明成像鏡頭第一實施方式之球差特性曲線 圖。 圖3為本發明成像鏡頭第一實施方式之場曲特性曲線 圖。 圖4為本發明成像鏡頭第一實施方式之畸變特性曲線 •圖。 圖5為本發明成像鏡頭第二實施方式之球差特性曲線 圖。 圖6為本發明成像鏡頭第二實施方式之場曲特性曲線 圖。 圖7為本發明成像鏡頭第二實施方式之畸變特性曲線 圖。 ^ 【主要元件符號說明】 成像鏡頭 100 第一透鏡 10 第二透鏡 20 第三透鏡 30 光圈 40 成像面 200 感測元件 210 141364554 > IX. Description of the Invention: [Technical Field] The present invention relates to imaging technology, and more particularly to an imaging lens. ^ [Prior Art] In recent years, with the development of semiconductor technology, image sensors applied to imaging systems, such as Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS) devices, At the same time as improving the picture element, it is developing towards miniaturization and direction to meet the consumer's requirements for imaging quality and portability of the imaging system. Correspondingly, the imaging lens needs to be improved in resolution and downsized to match the image sensor to form an imaging system with better imaging quality and small size. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide an imaging lens having a good imaging quality and a small size. An imaging lens that includes, in order from the object side to the image side, a first lens having a positive power, a second lens having a positive power, a third lens having a negative power, and a sensing element, wherein The imaging lens satisfies the conditional expression: D/TTL>1.23 0.3<G1R1/F1<0.4 where D is the size of the largest effective primitive of the sensing element; TTL is the surface of the first lens near the object side to the imaging surface Distance; G1R1 is the radius of curvature of the surface of the first 6 1364554 lens near the object side; F1 is the focal length of the first lens. The condition D/TTL > 1.23 limits the total length of the imaging lens; ^ 0.3 < G1R1/F1 < 0.4 ensures the balance between the total length of the imaging lens 100 and the spherical aberration and coma to ensure that the imaging lens has a better The advantages of imaging quality and miniaturization. [Embodiment] Please refer to FIG. 1. In an embodiment of the present invention, an imaging lens 100 includes, in order from the object side to the image side, a first lens 10 having a positive power, a second lens 20 having a positive power, and a negative light. The third lens 30 of the power and a sensing element 210. During imaging, light enters the imaging lens 100 from the object side, and then passes through the first lens 10, the second lens 20, and the third lens 30, and then converges on the imaging plane 200. A sensing surface 210 (such as a CCD or CMOS sensing surface (not shown) is disposed at the imaging plane 200 to form an imaging system. In order to reduce the length of the imaging lens 100 and have better imaging quality, the imaging lens 100 should satisfy the following conditions: (1) D/TTL>1.23 (2) 0.3<G1R1/F1<0.4 where D is sensing The size of the largest effective primitive of the component 210; TTL is the distance between the surface of the first lens 10 near the object side and the imaging surface 200; G1R1 is the radius of curvature of the surface of the first lens 10 near the object side; F1 is the first lens 10 The focal length. 7 1364554 tr condition (1) limits the overall length of imaging lens 100. Condition (2) ensures the balance between the total length of the imaging lens 100 and the spherical aberration and coma aberration to ensure that the imaging lens 100 has a good image quality. Preferably, the imaging lens 100 also satisfies the conditional expression: (3) 0.8 < G1R2 / F1 < 1.2 Condition (3) gives the radius of curvature G1R2 of the surface of the first lens 10 near the image side and the focal length F1 of the first lens 1 The relationship between the total length of the entire imaging lens and the spherical aberration and coma can be further ensured, and the overall length of the imaging lens can be further shortened and the manufacturing cost can be reduced. Satisfying G1R2/F1<1.2 shortens the overall length of the imaging lens 100, and satisfies 0 8<gir2, which prevents the image side surface of the first lens 10 from being excessively curved, resulting in difficulty in grinding the lens, and increases manufacturing cost. (4) -0.1<G2R2/F2<G2Rl/F2<-〇.〇2 Condition (4) gives the radius of curvature of the surface of the second lens 20 near the object side, G2R1, and the radius of curvature G2R2 of the surface near the image side. The relationship between the focal length F2 of the second lens 2 and the focal length F2 of the second lens 2 further ensures the balance between the total length of the entire imaging lens 1 and the spherical aberration and the coma. Further, the overall length of the imaging lens 100 can be further shortened, and the manufacturing cost can be reduced. (5) G3R1/F3<-1.5 (6) -l<G3R2/F3<-0.5 Condition (5) and condition (6) respectively give the radius of curvature G3R1 of the surface of the third lens 3〇 near the object side and the vicinity The relationship between the radius of curvature of the surface of the image side 8 1364554 G3R2 and the focal length F3 of the second lens 30 can further ensure the balance between the total length of the entire imaging lens 100 and the spherical aberration and coma, and the overall imaging lens 100 is improved. Image quality. On the other hand, in order to correct the chromatic aberration, the imaging lens 100 is also limited to satisfy the relationship: (7) Vdl > 52 (8) Vd2 < 23 ° wherein, in condition (7), Vdl is d light (wavelength is 587.6 nm, the same below) The Abbe number of the first lens 10; Vd2 is the Abbe number of the d-light at the second lens 20 in the condition (8). It can be understood that in order to suppress the influence of stray light on the imaging quality of the imaging lens 100, an aperture 40 may be disposed on the object side of the first lens 10 to mask stray light. The imaging φ lens 100 is further illustrated in the detailed description with reference to Figs. 2 through 7 below. In the specific embodiment, both the object side and the image side of the first lens 10, the second lens 20, and the third lens 30 are aspherical. Taking the center of the lens surface as the origin and the optical axis as X beat, the aspherical surface of the lens surface is: ch2 · + l + ^l-(k+l)c2h2 where C is the curvature of the center of the mirror surface, k The quadric coefficient kVFTF is the height from the optical axis to the lens surface, Σα/ indicates the accumulation of Aihi 9 1364554, i is the natural number, and Ai is the aspherical surface coefficient of the i-th order. The following are two preferred embodiments, and are respectively explained: ^ First Embodiment The optical elements of the imaging lens 100 satisfy the conditions of Tables 1 and 2. Table 1 below lists the optical surface of the object side to the phase side, the spherical shape of each optical surface, the radius of curvature (R) of each optical surface on the optical axis, and the optical axis from the object end to the image end. The distance between the face and the latter optical surface (D), the refractive index (nd) of the lens material and the Abbe number (Vd). Table 1 Optical surface spherical surface type RD nd Vd First lens object side aspheric surface 0.98 0.61 1.53 56 First lens image side aspheric surface 2.26 0.07 Second lens object side aspheric surface - 1.17 0.37 1.585 30 Second lens image side aspheric surface - 1.24 0.96 Third lens object side aspheric surface -10.00 0.38 1.53 56 Third lens image side aspheric surface 3.84 0.35 1364554 The aspherical coefficient list is as follows: Table 2 Aspherical coefficient First lens object side G1R1 First lens image side G1R2 Second lens Object side G2R1 Second lens image side G2R2 Third lens object side G3R1 Third lens image side G3R2 Α4 -0.0297 0.0148 -0.1782 0.0095 -0.1613 -0.1443 Α6 -0.0035 0.0169 0.0473 0.0339 0.0872 0.0538 Α8 -0.0282 -0.1359 -1.2170 0.3717 -0.0180 -0.0152 Α10 -0.0333 0.6288 8.1281 0.0818 0.0015 0.0021 Α12 -0.0211 0.0210 -15.8921 -0.3195 -3.4Ε-05 -0.0001 The spherical aberration characteristic curve, the field curvature characteristic curve and the distortion characteristic curve of the imaging lens 100 in the first embodiment are respectively 2, 3 and 4 are shown. In Fig. 2, the curves f, d and c are f-light (wavelength of 435.8 nm, the same below), d-light and c-light (wavelength is 656.3 nm, the same below) in the imaging lens 100. with). It can be seen that the spherical aberration generated by the imaging lens 100 of the first embodiment on visible light (400-700 nm) is controlled to be between -0.05 mm and 0.05 mm. In Fig. 3, the curves t and s are the tangential field curvature characteristic curve and the sagittal field curvature characteristic curve (the same applies hereinafter). It can be seen that the meridional field curvature value and the sagittal curvature value are controlled between -0.05 mm and 0.05 mm. In Fig. 4, the curve is the characteristic curve (the same below). It can be seen that the distortion variable is controlled between -5% and 5%. In the meantime, although the size of the imaging lens 100 is reduced, the spherical aberration, curvature of field and distortion 11 1364554 are controlled (corrected) to a small extent. Second Embodiment The optical elements of the imaging lens 100 satisfy the conditions of Tables 3 and 4. Table 3 below lists the optical surface of the object side to the phase side, the spherical shape of each optical surface, the radius of curvature (R) of each optical surface on the optical axis, and the optical axis from the object end to the image end. The distance between the surface and the latter optical surface (D), the refractive index (nd) of the lens material, and the Abbe number (Vd). Table 3 Optical surface spherical shape RD nd Vd First lens object side aspheric surface 0.98 0.59 1.543 56.8 First lens image side aspheric surface 2.05 0.08 Second lens object side aspheric surface - 1.22 0.38 1.585 30 Second lens image side aspheric surface - 1.26 1.05 Third lens object side aspheric surface -10.00 0.32 1.515 57 Third lens image side aspheric surface 4.05 0.35 The aspherical coefficient list is as follows: Table 4 Aspherical coefficient first lens object side G1R1 First lens image side G1R2 Second lens object Side G2R1 Second lens image side G2R2 Third lens object side G3R1 Third lens image side G3R2 12 1364554 A4 -0.0318 0.0044 -0.1949 -0.0006 -0.1803 -0.1529 A6 0.0075 -0.0565 -0.0303 -0.0176 0.0836 0.0530 A8 -0.0349 -0.1291 - 1.2707 0.3407 -0.0166 -0.0147 A10 -0.0463 0.5642 8.7958 0.1384 0.0021 0.0021 A12 -0.0183 -1.5272 -17.7776 -0.2671 -0.0002 -0.0002 The spherical aberration characteristic curve, the field curvature characteristic curve and the distortion characteristic curve of the imaging lens 100 in the second embodiment See Figure 5, Figure 6, and Figure 7, respectively. As can be seen from Fig. 5, the spherical aberration generated by the imaging lens 100 of the second embodiment for visible light (400-700 nm) is controlled between -0.05 mm and 0.05 mm. As can be seen from Fig. 6, the meridional field curvature value and the sagittal field curvature value are controlled between -0.05 mm and 0.05 mm. It can be seen in Fig. 7 that the distortion of the distortion characteristic curve is controlled between -5% and 5%. In the meantime, although the size of the imaging lens 100 is reduced, the spherical aberration, field curvature and distortion generated are controlled (corrected) to a small extent. The imaging lens of the present invention satisfies the conditional formula: D/TTL > 1.23, which limits the overall length of the imaging lens 100; 0.3 < G1R1/F1 < 0.4 ensures the total length of the imaging lens 100 and the spherical aberration and coma Balanced to ensure that the imaging lens 1 〇〇 has better imaging quality. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the present invention are intended to be included within the scope of the following claims. 13 1364554 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the system configuration of a preferred embodiment of an imaging lens of the present invention. Fig. 2 is a graph showing the spherical aberration characteristic of the first embodiment of the imaging lens of the present invention. Fig. 3 is a graph showing the field curvature characteristic of the first embodiment of the imaging lens of the present invention. Fig. 4 is a view showing a distortion characteristic curve of the first embodiment of the imaging lens of the present invention. Fig. 5 is a graph showing the spherical aberration characteristic of the second embodiment of the imaging lens of the present invention. Fig. 6 is a graph showing the field curvature characteristic of the second embodiment of the imaging lens of the present invention. Fig. 7 is a graph showing the distortion characteristic of the second embodiment of the imaging lens of the present invention. ^ [Main component symbol description] Imaging lens 100 First lens 10 Second lens 20 Third lens 30 Aperture 40 Imaging surface 200 Sensing element 210 14